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If a rock falls on Mars and there is no one to see it, will it leave a trace? Yes, and it’s a beautiful herringbone-like pattern, new research reveals. Scientists have now detected thousands of tracks on the red planet formed by rolling rocks. The team showed that delicate swaths of Martian dust and sand in the form of stripes surround the tracks, and many of them fade within a few years.
Rockfalls have been detected elsewhere in the solar system, including the Moon, and even a comet. But a big open question is the timing of these processes on other worlds – are they ongoing or have they occurred predominantly in the past?
A study has been published on these short-lived features on Mars. Last month in Geophysical Research Letters, He says such rock fragments could be used to detect recent seismic activity on the red planet. This new evidence that Mars is a dynamic world goes against the notion that all of the planet’s exciting geology happened long ago, said Ingrid Daubar, a planetary scientist at Brown University who was not involved in the study. “For a long time we thought Mars was this cold, dead planet.”
To arrive at this finding, planetary scientist Vijayan, who uses a single name at the Physical Research Laboratory in Ahmedabad, India, and his colleagues analyzed thousands of images of the equatorial region of Mars. The images were captured by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter from 2006 to 2020, revealing details as small as 10 inches.
Dr. “We can distinguish individual rocks,” Vijayan said.
The team manually looked for chain-like features in the sloping walls of impact craters – a distinctive signature of a tilted rock – in the sloping walls of impact craters. Dr. Vijayan and his collaborators saw more than 4,500 rock tracks, the longest of which was over a mile and a half long.
Dr. Sometimes the tracks change direction, and sometimes new tracks branch out suddenly, Vijayan said. Such shifting tracks are probably evidence that a boulder shattered in mid-autumn and its offspring continued to jump downhill.
Roughly one-third of the marks the researchers examined were missing from early images, so they must have formed since 2006. The splash marks of all of these young pieces are framed by a strip-shaped pile. Mars regolith. Researchers, Dr. Nicknamed the “rockfall ejecta” by Vijayan and his colleagues, this material suggests it is ejected every time a rock hits the surface.
And this rockfall material is temporary: By tracking the same traces in images taken at different times, the team found that the rockfall tended to remain visible for only about four to eight years. Researchers suggest perpetual winds Redistribute dust and sand on the Martian surface and wipe out the ejecta.
The team suggests that this implies that a rock had been displaced recently, as the rockfall ejecta is fading very quickly. And a common cause of rockfalls on Earth and elsewhere is seismic activity.
Dr. Vijayan and his collaborators found that roughly 30 percent of the rock tracks in the rockfall ejected samples were concentrated in the Cerberus Fossae region of Mars. This is much more than expected, as this region covers only 1 percent of the study area, the researchers say. Dr. “There are lots of rockfalls in the surrounding craters,” Vijayan said. “A few even have multiple falls in the same place.”
Alfred McEwen, a planetary geologist at the University of Arizona and principal investigator of HiRISE, said he was not involved in the research. Geography near Cerberus Fossae, i.e. Tharsis volcanic regionmakes the area prone to seismic activity. Dr. “These huge masses of dense rock loaded onto the surface create tensions across the crust around Mars,” said McEwen.
Hundreds of mars earthquakes have been detected since 2019. NASA’s InSight spacecraftand the two biggest occurred last year In the Cerberus Fossae region.
In the future, Dr. Vijayan and his collaborators plan to expand their analysis to include the polar regions of Mars. Dr. McEwen said that although the device has significantly exceeded its design life, the HiRISE camera will hopefully deliver on that. “HIRISE is still going strong.”
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